Greetings
I have been meaning to write of my experiences of upgrading the brakes while doing a body-off restoration of my 1973 J4000. My reasoning is to possibly help others who may contemplate this conversion in the future. As a bit of background, personally, I am a proponent of restoring these vehicles back to their original glory. With that being said, I am not a purist. I find some modern safety features are a plus, especially if the vehicle is to be used frequently, as this one will be for pulling a vintage travel trailer. I have done both the front and rear conversions to disc. The rear is the Dana 60-2 and the front is the closed knuckle Dana 44. The rear is the subject of this post. The older style axles and the "outboard" springs intrigue me. The aesthetics hearken back to a more basic and simpler time and this is why have decided to keep them. I will probably do several posts as one, all encompassing post might bore the heck out of most.
The parts list:
1) Rear Disc Conversion, #2580J20PB.
The kit was purchased from TSM MFG. Co., Inc. out of Castle Rock, Colorado. I paid around $750.00 (Spring of 2022) for the kit but I see it now sells for $921.00 www.tsmmfg.net/jeep-j20-complete-rear-d ... 80j20.html
David was amazing to deal with and prompt with his replies. I will say that I asked several questions and he was always gracious and helpful. The kit is full of well made items and complete but there were some negatives to report. The kit comes with a spacer (measures 0.117" thick), which is used to take up the space that the backing plate (measures 0.187" thick) would normally reside, it was too thin. I spoke with David, and he said in 25 years of selling the kit he had not encountered this anomaly but was able to send a Ford style spacer at 0.178" thick. After purchasing 0.010" shim stock I was able to use this spacer. This spacing is critical since it applies the correct pressure to the outer axle seal that in turn retains the axle bearing. Another issue I had was the spacers provided to allow the caliper to be centered on the rotor did not allow for proper clearance. The bracket that mounts the caliper to the axle bearing retainer/main mount had to be modified. An finally, the I.D. of the outer bearing retainer/ caliper mount had to be opened up to clear the lips of the outer seal. Had this retainer I.D. been left as-is, it would have crushed the outer rubber lips leading to premature failure down the road. The kit was good quality, customer service from TSM was top-notch, and the kit was comprehensive to the point of including new stainless braided flex hoses with weld-on axle tabs. Now maybe my issues with kit fitment were that I have an odd Dana 60-2 or possibly it had been modified over the last 50ish years, I do not know but in my experience, extensive modifications had to be made. It could have been worse had TSM not stood behind their product.
2) Rear Axle Bearing, Retainer, Outer Seal, Inner Seal
When installing the above conversion kit, the axle bearings and seal must be changed due to the caliper mount/outer bearing retainer captured between the bearing and the axle flange. My search for these components was exhaustive but productive. I will exaggerate and say that NOBODY lists these parts by application anymore. Hopefully, my experiences here will help. The parts are readily available. KEEP THESE PART NUMBERS HANDY!!!
Rear Axle Bearing, Spicer #565904, purchased from RockAuto $57.79
Rear Axle Bearing Retainer, Spicer #35961, RockAuto $7.30
Rear Axle Inner Seal, Spicer #35512, RockAuto $3.91
Rear Axle Outer Seal, CR Seals, #21244, Purchased from CR on Ebay $22.91
Cheers!